Goodwill and Intangible Assets

3 Months Ended

Mar. 31, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Intangible Assets

6.   Goodwill and Intangible Assets. The change in the carrying amount of goodwill for the three-month period ended March 31, 2021 is detailed as follows (in thousands):

	March 31, 2021
Goodwill balance at January 1	$	363,533
Effect of foreign exchange		(1,033)
Goodwill balance at March 31	$	362,500

Total accumulated goodwill impairment losses aggregated to approximately $8.3 million as of March 31, 2021 and December 31, 2020. We did not have any goodwill impairments for the three-month periods ended March 31, 2021 and 2020. The total goodwill balance as of March 31, 2021 and December 31, 2020 was related to our cardiovascular segment.

Other intangible assets at March 31, 2021 and December 31, 2020 consisted of the following (in thousands):

	March 31, 2021
	Gross Carrying		Accumulated		Net Carrying
	Amount		Amortization		Amount
Patents	$	24,362	$	(6,929)	$	17,433
Distribution agreements		3,250		(2,369)		881
License agreements		14,418		(7,010)		7,408
Trademarks		30,255		(13,131)		17,124
Customer lists		35,052		(29,586)		5,466
Total	$	107,337	$	(59,025)	$	48,312

	December 31, 2020
	Gross Carrying		Accumulated		Net Carrying
	Amount		Amortization		Amount
Patents	$	23,669	$	(6,460)	$	17,209
Distribution agreements		3,250		(2,319)		931
License agreements		14,453		(6,647)		7,806
Trademarks		30,273		(12,414)		17,859
Customer lists		35,154		(29,103)		6,051
Total	$	106,799	$	(56,943)	$	49,856

Aggregate amortization expense the three-month periods ended March 31, 2021 and 2020 was approximately $12.5 million and $15.0 million, respectively.

We evaluate long-lived assets, including amortizing intangible assets, for impairment whenever events or changes in circumstances indicate that their carrying amounts may not be recoverable. We perform the impairment analysis at the asset group for which the lowest level of identifiable cash flows is largely independent of the cash flows of other assets and liabilities. We determine the fair value of our amortizing assets based on estimated future cash flows discounted back to their present value using a discount rate that reflects the risk profiles of the underlying activities. We did not identify indicators of impairment in any intangible assets based on our qualitative assessment for the three-month periods ended March 31, 2021 and 2020.

Estimated amortization expense for the developed technology and other intangible assets for the next five years consisted of the following as of March 31, 2021 (in thousands):

Year Ending December 31,	Estimated Amortization Expense
Remaining 2021	$	37,320
2022		48,634
2023		47,454
2024		44,404
2025		42,548